If you leave the beaten path in Allendale’s Celery Farm Natural Area, cross the Brotherton Bridge and take one of the two narrow trails that head north, you'll go through an area known as Barbara's Bog.

To look at the flat wooded area, you’d never know that it was once a cow pasture, and a very special one at that. It was here, in the mid-1950s, that a World War II veteran got an idea that helped revive the bluebird population of northern New Jersey.

The land was owned by a local milkman, Fred Rogers, who let townsfolk picnic there. Back then, my friend Stiles Thomas was a young insurance broker and bird watcher who had noted that he was seeing fewer bluebirds in the area.

One beautiful spring day, as Stiles, his wife, Sis, and some friends spread out their lunch on a blanket in Rogers’ pasture, Stiles saw a bluebird. He ran home, grabbed a nesting box he had built and raced back to the meadow.

No sooner had Stiles secured the box to a nearby tree than a bluebird flew in.

A lightbulb went off. The reason Stiles hadn’t been seeing many bluebirds was that, as more and more housing developments replaced meadows and woods in North Jersey, these beautiful blue and reddish birds had fewer tree cavities in which to build their nests.

Stiles decided to help them out. Inspired by an Illinois doctor who’d put up thousands of bluebird boxes over two decades, Stiles started to build birdhouses out of old orange crates. By trial and error, he learned how to make them the most attractive to prospective bluebird tenants, including his discovery that the nesting boxes had to be at least 300 feet apart or the bluebirds would spend their time fighting over the turf instead of starting families.

A female bluebird at the opening of the nest box. Just watch out for those dang house sparrows.(Photo: Jim Wright)

Stiles soon put up the nest boxes, free of charge, in every meadow where the property owner would allow. Stiles also worked hard to get others involved, publishing articles and offering free instructions on building bluebird boxes to anyone who’d send him a self-addressed stamped envelope.

In all, Stiles put up almost 200 bluebird boxes over one five-year period in Allendale, Saddle River, Upper Saddle River, Wyckoff, Ramsey, Franklin Lakes, Mahwah and Waldwick. He monitored all of them once a week during nesting season, creating two routes of 10 miles each. Over that stretch, 144 pairs of birds nested successfully, including 44 that had second broods in the same year.

His success was trumpeted in an Audubon magazine article about “the Bluebird Man of Bergen County,” and in the Reader’s Digest.

Fast forward more than six decades to early 2016, when Stiles heard that a friend had seen a bluebird in her meadow near New Paltz, New York. He insisted on driving there and putting up a bluebird box he had built, free of charge.

Six weeks later, when spring was going full throttle, a pair of bluebirds set up housekeeping. They’ve had a couple of broods of baby bluebirds there since then.

But Stiles was only getting started. If you send a stamped, self-addressed envelope to Stiles at Bluebird Plans, Box 75, Allendale, NJ 07401, he will send you a free copy of a 1959 magazine article called “5 Ways to Attract Birds” — which includes his original plans. That way, you can build your own bluebird box and keep up the tradition. Or buy one. If bluebirds don’t move in, other birds will.

The Bird Watcher column appears every other Thursday. Email Jim Wright at celeryfarm@gmail.com.